Rotary multiple contact switch



Nov. 10, 1953 Filed March 1 1949 F. KRAHULEC ROTARY MULTIPLE CONTACTSWITCH 5 Sheets-Sheet 1 INVENTOR.

F. KRAHULEC ROTARY MULTIPLE CONTACT SWITCH Nov. 10, 1953 S Sheets-Sheet2 Filed March 1 1949 ill lllll llll ll w .[lmllllllllll HI '7 INVENTOR.E'eci A ia/2x490 Nov. 10, 1953 F. KRAHULEC ROTARY MULTIPLE CONTACTSWITCH Filed March 1, 1949 5 Sheets-Sheet 4 INVENTOR. f'7ed l razzla BYMMMW Nov. 10, 1953 F. KRAHULEC 2,658,963

ROTARY MULTIPLE CONTACT SWITCH Filed March 1, 1949 5 Sheets-Sheet 5 IN VEN TOR. 7 ?eci fizz/2241 96 Patented Nov. 10, 1953 ROTARY? MULTIPLECONTACT SWITCH iFredsKrahuleafSkokie, Ill.,"nassignorst to ArtC. NielsenCompany, Ghicago,-lll.; acorporation of Illinois Application March 1,1949',*Serial'No.'78,'921

L 19 .Glaims. 31:1

The present inventionrelatesto a rotaryrmultiple contact switch and imsome respects is: an improvementonthe switch disclosed incopendingapplication Seria1-'No;-.'Z,648 of- Rahmel; filed February 11,1948; andassigned tQ thesame-assignee as the present application.

Multiple rcontact'rotary switches have many applications. ..r :In:.:the'arran'gement disclosed in the above mentioned copending Rahmelapplication av multiple contactswitch is employed-in connection withadevice: for recording the listening. habits of:i'wave signa1 receiverusers,. the switch being v:usedi 'toiiconvert. variable 1 positions to aplurality: ofuu'niformlyf spaced .indications and records thereoi. on= arecording-clement or tape. Byavirtue of em'ployingwsuch a switch whichin effect :servesms. a channelizing-swi-tch, the tracespro'ducedfonisuch a re'cording element or tape mayyfor exa-mple,l .beequally spaced transversely ofithe' tape regardless. of the actualrelative relationship. -.-offl-.the-. different channels with-respectsto frequency. Where. a? multiple contact switch is employed inconnection with recording devi'cesi-iofzithei type! mentioned, it. :isessential.thatxthe contact positions he adjustable and also;that theeffective widths of thecontacts be adjustable; This-ris' becausethewarious channels to which a wave signal receiver is likelycto betunedare spacede'inxquite a haphazard manner across the frequencyspectrum. ."Consequently, it is essential that theflpositions .of thesecontacts may be adjustable so.:.that1;effectively; as farlas therecording elementsisaiconcerned, .theechannels are equallyspa-cedr 1v Itrwill, :furthermore, be apparent to :one who'thas' had; any contact withtuning a radio receiverlthat certain stations may be tuned in over.asu'bstantial area-on the'tuning dial, whereas othenstations are-tunedin on :only a very small increment ofthextuning dial. bviously torecordcorrectlythe:tuningcondition of the receiver, it is :essentialthat. such ::variab1e positions of the tuning diarfor'the same channelwill efiectively 'controli'ionly a; single .contact of the rotaryswitch.

Such a rotary multiple contact-switch must be associated withthe-wave-signalreceiver in'such a manner thattuning of thereceivercauses movementof the. switch; It: is :important ither'efore, that sucha rotary .switchhave a veryilow torque so as not to'interferevwith thetuning actionto any substantial.;extent;isincef the user. of thereceivershould generallyibeunaware of any differ- ,ent receiver operation:caused byattachments to l the "receiver.

: In certain cases citsis desirable to convert :the

2 tuning position ofsuch awavesignalreceiver to someform of code-whichcan readily berecorded -on a-movablerecording-element. The rotarymultiplecontact switch of the present invention mayreadily be employedfor this purpose when combined-with a position switch as mentioned aboveand as will become apparent from the following-description. Accordingly,it'is an' object of the present invention toprovide-a new and-improvedrotary multiplec'on-tact switch.

It is another object of the present-invention to provide a rotarymultiple contact switchin which the contacts may be selectivelypositioned in various ways with respectto each other and in h which bylimitedmovement of the contacts the 'efiectivezwidth :thereof may-becontrolled.

A further object of the present invention is to provide a new andimproved :m'ultiple contact switch having very lowtorque requirements.1A stillfurtherlobject: of the present invention is to provide a rotarymultiple .contact switch of sturdy,- foolproof constructiom in whichwiping action of the switch contacts occurs. to insure good. electricalwengagement' between 7 adjacent conductingparts.

It is a further object of :the present invention to'uprovide arotary-multiple contact switch of relati-velyfew: and. simple 1 parts,in which" the contact sequence .isrsuch i that when properly =as-.sociated:with .asuita'ble circuit, operation thereof will result in theproduction- 0f pulses to form a code or .the like.

Further .objectsand. advantages of the present invention-rwill becomeapparent as the following description-proceeds and the' features ofnoveltywhich characterize-the invention will be pointed out with'particularity in the claims anexed' to and forming; a part of. thisspecifica- ."For a better understanding of the presentiinvention,referencemaybe hadto the accompanying drawings,i:inwhich? Fig. .1. isa:- perspective view of one embodiment of; a z multiple: contact:rrotary "switch associated with the resonant irequencyvarying device ofa wave; signal receiver i Fig; 2Lisl antenlarged sectional View takenonline 2-2 of Fig. 1;

- Fig. 3 is aperspective view of one of the contacts of therotary-multiple conta-ctnswitch of -.tiple. contact switch-illustratinga modification of :the present invention;

Fig. is a sectional view taken on line 55 of Fig. 4;

Fig. 6 is an elevational View of a rotary multiple contact switchillustrating still another embodiment of the present invention;

Fig. 7 is an elevational view of the switch of Fig. 6 viewed from theopposite side to that shown in Fig. 6;

Fig. 8 is a top view of the multiple contact switch shown in Fig. 6 ofthe drawing Fig. 9 is a perspective view showing the mul-- tiple contactswitch of Fig. 6 associated with the tuning apparatus of a wave signalreceiver;

Fig. 10 is a top view of a rotary multiple contact switch embodyingstill another modification of the present invention and comprising whatat present is considered to be the preferred embodiment of the presentinvention;

Fig. 11 is a sectional view taken on line H--l| of Fig. 10;

Fig. 12 is a sectional View illustrating the associated contacts of onecircuit controlling element of the multiple contact switch whenacljusted for substantially minimum contact width;

Fig. 13 is a view similar to Fig. 12 with the switch adjusted forsubstantially maximum contact width;

Fig. 14 is a bottom view of the switch of Fig. 10;

Fig. 15 is an exploded view of a portion of a rotary shaft which may beemployed in the switch of Fig. 10 to illustrate a detail of the presentinvention;

Fig. 16 illustrates an enlarged assembled view of the portion of therotary shaft shown in exploded form in Fig. 15;

Fig. 17 illustrates one form of cam which may be employed in connectionwith the rotary switch of Fig. 10;

Fig. 18 is a view somewhat similar to Fig. 11 showing a modifiedarrangement of the cam supporting means when the rotary switch isemployed as a coding switch;

Fig. 19 is a partial perspective view of the cam supporting means shownin Fig. 20;

Figs. 20 and 21 are two forms of cams which may be employed with therotary multiple contact switch of Fig. 18;

Fig. 22 is a bottom view of a multiple contact rotary switchillustrating still another embodiment of the present invention; and

Fig. 23 is an enlarged sectional view taken on line 23-23 of Fig. 22.

Although the rotary switch of the present invention has many differentapplications, it is especially adapted for use with devices andapparatus for recording the listening and/or viewing habits of wavesignal receiver users where instrumented methods for obtaining thisinformation are employed. By instrumented method is meant a methodwhereby information with respect to the listening habits of wave signalreceiver users is obtained by instruments or devices associated with thevarious wave signal receivers of a representative group of the public soas continuously to record with respect to time the tuning condition ofsuch receivers, thereby providing the basic information from which ananalysis can be made. In connection with such analysis, it will beunderstood that the listening habits of users of wave signal receiversof a rep resentative group will be recorded and the selection of theparticular homes of such representative group will be made on the basisthat all the various factors affecting any process of sampling publicopinion such as the number of potential 4 listeners, religion, economicaffluence, etc. are accounted for on a weighted basis.

In any particular locality it has been found that wave signal receiversare tuned to the various stations of a particular group of stationsalmost exclusively. By that is meant that in any particular area,perhaps four to eight stations are regularly listened to and althoughthe receiver may be capable of receiving many other stations, it israrely tuned to such other stations for reasons such as poor reception,duplication of program, or the like, Consequently, if the tuningposition of a wave signal receiver across the frequency spectrum for apredetermined number of channels usually tuned in by the receiver wouldbe used to control a predetermined number of contacts of a multiplecontact switch, it is apparent that the operation of such switch inresponse to the tuning of the receiver may be used to produce a controlfunction such as re cording the tuning condition of the receiverdireotly on a recording element or for producing a code which mayreadily be recorded, or performing any similar function.

Referring now to Figs. 1 to 3 of the drawings, there is illustratedsomewhat schematically the resonant frequency varying means, generallydesignated at 30, of a conventional wave signal receiver. This resonantfrequency varying means has been specifically illustrated as a variablecapacitor, although it might equally well comprise some other suitabledevice. Associated with the resonant frequency varying means 30 is amultiple contact rotary switch 3| forming one embodiment of the presentinvention. As illustrated, the rotary switch 3| comprises an insulatingsupport 32 which is suitably mounted adjacent the resonant frequencyvarying means 30 of a wave signal receiver. Mounted on the insulatingsupport 32 is an adjustable element generally designated at 33, forsupporting a stationary contact support 34 in the form of a portion of atorroid, preferably formed of insulating material. A complete torroidcould be employed but since with conventional wave signal receivers onlyabout degrees of a tuning dial are employed, a portion of a torroid issufficient.

Mounted at spaced points along the torroid portion 34 are a plurality ofstationary contacts 35, which contacts, although termed stationarycontacts, are capable of having limited relative movement. Thesecontacts 35, best shown in Figs. 2 and 3, each comprise a triangularshaped member having substantially zero width at one end thereof and anappreciable width at the other end thereof and are adapted to be bentaround the torroid portion 34 so as to form a plurality of spacedcontacts, the spacing of which may be adjusted in any predeterminedmanner. These contacts 35 are adapted to be electrically engaged in asequential manner by a movable switch arm 3i pivotally mounted about thegeometrical center of the torroid having the por tion 34. The switch arm31 in moving through an angle of 180 degrees or thereabouts,successively engages the contacts 35. These contacts 35 will bepositioned in various ways along the torroid portion 34 in dependenceupon the particular channels to which the associated wave signalreceiver is likely to be tuned, thereby providing adjustably positionedcontacts,

In order to provide variable contact widths, the contacts 35 may berotated about the cross section of the torroid portion 34 so as toexpose the-desired; width thereof to -the moyablerswitch Each.of.the.contactsaiiis provided with aport onfibwhichis connect d toa'suitable conaduct rdfi fo mns apartof. acab .dfl-wc m extend to anydesired controlcircuitnot shown. 1:, t 1 e un rstood-that the-m v blewit arm fl is connected .by suitable means with the eson re uencywa ymsde f a re For example, the supporting shaft 4 l, of the movb e-s itch.rmt'tvm s t e onnect ir ct y arm-. 3land; a suitable control vcircuihmay. be

. rendered effective to perform anydesired control function forrecording the ,tuning conditioner the receiver. The details ofone-such.- control arrangement are fullydisclosed in the copending 1Rahmel application referred .to above.

-In view ofthe detailed description included above, particularly'withreference to Figs. 1 to 3 ofthe drawings the operation of therotaryswitch described above will be apparent to those skilled .m theartand-no further discussion thereof is includedherein. It .will beobvious that there has been provided a variable position, variable widthcontact, emultiple contact switch.

Referring vto Figs 4 and 5 f the drawings,

'there is disclosed another embodiment of the present invention intheform of a rotary switch generally designated at 4 5. This rotary switchalso comprises an insulating support designated as 46, which has anarcuate groove 41 defined therein. -A rotatable switcharm-48 is mountedfor rotation upon ashaft tlfi journaledin suitable supports, suchas Wandwhich may form an integral assemblywith the insnlating support it.

As illustrated, the movable switch armAB isbiased by means of atensionspring 52 against a stop 53, thereby insuring returnof saidarmJlS- to its initial position; shown in Fig. 4 when any; force tendingto rotatethe shaft 49 against the bias of the spring 52' is removed.Such an'arrangement lends itself very well for :usewith a force ,7transmitting device capable of'transmitting a force inonlyone'direction, a well known example i of which is the. Bowden wire.

vIn accordance with the present invention, there are supportedwithin thearcuate groove 4'! a plurality of contacts 55 having an. elongatedconswitch arm 43. is ,positioned substantially 'tangetially to thegroove 41, it isapparent-that the switch arm 48 tact surface adaptedtobe engaged by the movable If theelongated contact surface .contactsthe maximum effective area thereof or,

in-other words, a maximum effective contact Width is provided. On theother hand if the elongated contactportionis substantially perpendicularto a tangent to the groove, a very narrow efiective contact is provided.This will be obvious from an examination; ofFigs. 4-and 5 of thedrawings. Preferably, as isbest shown in Fig. 5, each contact is ineffect the headof a screw 51 which is clampedby means of a nut 58 into apredetermined position along thegroove 4'1 and also withapredetermined.orientation to provide the, desired effective contactwidth. A suitable electrical terminal .59 to which electricalconnections can readily be made, is also clamped lntopositionby.the,,screw. 5 1 and the nut'58.

It-will be understood that the shaft. maybe a multiple contactrotaryswitch generally designated by the reference numeral 65. Thisswitch,

like, the precedingembodiments, also. comprises I a stationarydnsulatingsupport 66, which. may be mounted in any suitable manner adjacent a wavesignalreceiver bymeansof. a suitable angle plate -61. fastenedby-fasteningmeans 68. to a support generally designated at 69. Theinsulatingsupportlifi and the anglemember 61 support-for-relativerotation with respect thereto. a vsuitable. .rotatable shaft .10 towhichis fixed a.rotatable. disc 1| having mounted thereona'suitablesmovable switcharm 12 having asubstantial width near the axisof rotation. of .thedisc, 7 land agradually decreasing widthas the,peripheryof the discfll is approached. It willbe apparentfrom..the,description thus far. thatthe switch .65. differs. from theswitches 3| and 45 in that the rotatablecontact member, such. as 12, isprovided .witlrvariable widths as contrasted .with ,the relativelystationary contacts in theswitches 3| an-d,'45, which are providedwithvariable widths.

In accordance with the a present inventiom a plurality ofrelativelystationary. contacts.@.de

vided, which are preferably. .in theform.,of.resilient wire-likecontacts adjustably supported from suitable .supportingmeans M- mounted.on the stationary insulating supportjfi. Thesupporting means Marerotationally adjustable so that the angular position .of.the particularcontact arm 13 may be-adjustedin any .desiredman- ,ner. .Moreover, the,contact arms .13 extend through suitable-openingsin. the members 214and are clamped. thereto bysuitable clamping-means such, for example, asthe. screws, 15. By; changing the length ofthe, contact ,portion .13extending out of the vsuplwrt. 14,. theefiective; position .of thecontacts may becontrolled inany desired manner and bychanging,theangular relationship of thewire-like contacts. 13..any desirablewidthv of the. rotatable switch .arm J2: maygbe rendered effective toproduce the desired effective variable .width v contact.

For the purpose of causingrotation 'ofthe disc (I andv oonsequentlythe.movable contact. arm. 72 in response to..a forceapplied thereto. ,inonly one direction, there is provided a; torsion spring" which tends tobias, therotatabledise'llto the position shown in Fig. .8 of thedrawings. The rotatable shaft "I0 is provided with a pulley-like member19 about which themovable. portion of oneend of a Bowden wire v8U may bewrapped, as indicated at 89a, the Bowden wire being suitably supportedfromrthestationary insulating support '16 by means of the. member 8|.

In Fig. 9 .of the drawings there is illustrated the interconnectionbetween theswitch '65 wandthe wavesignal receiver, onlytheresonantfrequency varying means 82 of-which is shown. The end b of themovableportion-of theBowdenrwire 80 remote'from the; switch :65 isillustrated as :being wrapped around asuitable. drum-.;.83 which .atedwave signal receiver. -,Rotationof theytuning shaft will apply a tensileforce to the movable portion of the Bowden wire 80 with the result thatthe disc II is rotated against the torsional force of the spring 11, andthe stationary contacts I3 are selectively rendered effective as theyare engaged by the movable switch arm I2.

Although only five stationary contacts 13 are illustrated, it will beapparent that a great many more might be included if additional contactsare necessary or desirable. The members 74 are connected to suitableconnectors 84 to which electrical connections can readily be made.

In view of the detailed description set forth with respect to the switch65 disclosed in Figs. 6 to 9, inclusive, of the drawings, the operationthereof will be readily understood by those skilled in the art and nofurther discussion is included herein.

What is at present considered to be the preferred embodiment of thepresent invention in so far as a position switch is concerned isdisclosed in Figs. 10 to 17 of the drawings. This multiple contactrotary switch generally designated at 90 comprises an insulating support9| of generally rectangular configuration having defined therein achamber 93 for receiving a rotatable or movable shaft member 94. Asillustrated, the shaft 94 is journaled in side walls 9 la and 9Ibforming a part of the insulating support 9I. The insulating support 9|,as is clearly shown in Fig. 11 of the drawings, effectively comprisestwo molded parts 95 and 96 which in the final assembly are bolted orotherwise secured together. In the illustrated embodiment, suitablebolts 91 are provided for this purpose and preferably the heads and nutsof the bolts are disposed in recesses so as not to protrude beyond theedges of the insulating support 9|.

The portion 96 of the insulating support is provided with a plurality ofparallel slots 99 defined between narrow members I which are in manyrespects quite similar to the teeth of a comb, except that the free endsof the teeth are interconnected by a member 96a to give rigiditythereto. defined by the teeth I00 are a plurality of relativelystationary wire-like contact fingers, generally designated by thereference numeral I02. These contact fingers are mounted in cantileverfashion with the corresponding ends thereof clamped between the members95 and 95 defining the insulating support 9|, as is best shown in Fig.11 of the drawings.

If desired, one of the members 95 or 96 may be provided with serrationsspaced in the same manner as the slots 99 to hold the wire-like contactfingers I02 in proper spaced relationship. However, it has been foundthat the ends of the members can be suitably clamped between the members95 and 96 without the use of the serra- .tions.

For the purpose of determining the normal position of the wire-likecontacts I02 within the slots I00, the free ends of the wires I02 areeach adapted to engage with an adjustable stop member I03. Theseadjustable stop members are preferably threaded in tapped openingsdelined in the member 95, as is clearly shown in Fig. 11 of thedrawings, and the inherent resilience of the wire contact members causesthem to be biased against their respective stop members I03. The stopmembers are illustrated as being staggered in two rows and to preventtheir coming loose, once the adjustment has been completed, a suitableresilient member I formed Disposed within the various slots 99 of rubberor the like is forced between the two rows of stop members I03, as isclearly shown in Fig. 14 of the drawings. This member I05 remains wedgedbetween the two rows of stop members I03 at all times.

As is illustrated in Figs. 11, 12 and 13 of the drawings, each of thewire-like contact members is provided with a V-shaped contacting portiondesignated as I02a, the purpose of which will be come apparent from thefollowing description.

In order electrically to engage in a selective manner the relativelystationary contacts 92, there are mounted on the rotatable shaft 94 aplurality of spaced contacts generally designated at I06, which have acam-shaped configuration and cooperate with the contacts I02 in a mannerto be described hereinafter so as to produce a variable width contact,as desired. Preferably the rotatable shaft 94 is provided with aplurality of spaced annular grooves I01 for receiving therein thecontacts I09. The contacts I09 preferably have two flat sides Nita andI09?) engageable by a suitable wrench so that the contact whichpreferably frictionally engages the portion of the shaft 94 within thegrooves Ill? may be rotated to any desired predetermined positionrelative to the shaft 94. Also, as illustrated, the contacts I99 have atriangularly shaped portion I990, which is adapted to engage with thewire contacts I02, as clearly shown in Figs. 11, 12 and 13. It will beapparent from an examination of these figures that the contacts I00 inef-- fect comprise a pair of legs which are biased into intimatefrictional engagement with the base of the grooves I01, to maintain thecontacts I06 in any predetermined position to which they are set.

With the construction described thus far, it will be understood that themultiple contact rotary switch is inherently provided with variablewidth contacts which will be obvious upon examining Figs. 12 and 1.3 ofthe drawings. When the stop member I03 of any particular contact I02 iscaused to protrude a maximum extent above the housing 9I, the portion1020, of the wire-like contact I92 can be moved to a position such thatit never engages with the associated rotatable contact I09. In Fig. 12of the drawings the stop I03 is positioned so that the contact I06 justtouches the stationary wire-lilre contact I02, when the high point ofthe contact I06 which effectively is a cam surface is moved directlyopposite the V-shaped portion late. With this positioning it is apparentthat a contact having a very narrow effective width provided. When thestop I03 is adjusted so as to protrude to a much less extent from theinsulating support 9| a much greater surface of the contact I08 iseffectively engageable by the wirelike contact I02 in response to therotation of the shaft 94, and as is best shown in 13, engagement of thecontacts I92 and I99 occurs over a substantial rotation of the shaftIil'i. By appro priately adjusting the stops I03 between the positionsshown in Fig. 12 and Fig. 13, any variation in contact widths betweenthese limits may be obtained.

It will be understood that the shaft 94 may be rotatable through anentire 360 or as illustrated in Figs. 10 and 14 the rotary shaft 94 maybe rotatable through an angle less than 350, As illustrated the shaft 94is adapted to be rotated by means of a Bowden wire device or the likeand to this end a suitable drum I08 is attached to one end of the shaft94. A cord I09 which may 9 form a portion of the Bowdenwire-arrangementis adapted to be wrapped aroundthe-drum H1811 A suitable :torsion spring'-I I0 having-. one end fa'stenedtoa support III. associated with thehousing-9| may be providedto-return; the shaftv 94 -to :an initialposition :wheneverwno. rotationala force isapplied to the shaft94Jbyvther:cordJIlQc and the; drum 198.. If. desired; a =.double: Bowdenwire arrangement may be employed whereby the. springa-IIII maybedispensed ffwith. Also :the; drum :xI (mg-instead of being. directly.connected to the shaft94, may bedrivingly connected through. a suitablegear arrangement:

It .will be understood thatv any-reasonable;num:- ber of rcontacts maybe: provided-for .a .multiple switch'of the type shcwn:in- -Fig.rl 0,-the addi-i tional contacts merely. increasing the I length. of 1- theswitch. Occasionally it becomes desirable to...

provide; a multiple contactmultiple phase switch. This canreadily. beaccomplished-withthe switch. SBsmer-ely by electrically insulating.certain. con-. tacts/from certain other contacts... With thearrangement:described thus. farthe. contacts I I321.

longitudinal recess H5, adapted to receive aninsulating sleeve IIliwhich insulatingsleeve has an internal diameter substantially of thesame. order as the diameter ofthe extension- Ilia of the shaft portionH2. A suitable insulating.

Washer-II! is adapted to be disposed betweenathe 1 shaft portions H2 andH3, and theshaftportions are adapted to be united into an integral;

structure as shown in Fig. '16. ofthe. drawings by: means ofa press fitwhich is vreadily'possible by virtue of the compressibility of "the;insulating sleev II'EiJ". A sufficiently strong shaft-:MRwith" regard totorsional force applied thereto isread-w ily obtainable in. view of therelatively small torqueinvolved. It .will be apparent-thatanycontactsI05 associated with the shaft portion H2 will be completely insulatedfrom.any-con. tacts I06 associated with thegrooves .IO'I in.theshaftportion-I I3.

In? view -of the detailed description included above the operation ofthe variable position, vari: able width, multiple contact switch shown.in Figs. 10 to 17, inclusive, will readily, be ,understood by thoseskilled in the art and Loo-further discussion thereof is includedherewith.

It hasbeeniound that the multiple; contact switch shown in Figs. 10 to17; inclusiveis ;very satisfactory in applications where it is desiredto produce a series of electrical pulses with the switch employed as asort of commutator; In such'a caseof course, the shaft Sim-continuallyrotatable as, for example, by being directly cou- I pledto a driving motor or the like."- One-suchapplication is disclosed andclaimed in copending- Krahulec et al. application Serial No: 147,304;-filed March '2, 1950, and assigned-tothe same as equally spaced or timedpulses in a pumber of individual circuits, -the-samecams or contacts106" described above may be'employed with-the shaft 94" =.except that-'-the --contacting portions I 960 ofthe cams I06 are angularlydisplaced byequa-l incrementsaroundtheshaft 94-. This can readilybeaccomplished,"for-example, byproviding-the shaft-' with a helicalgroove, a sma l]. portion of which is indicatedat-IZEI in-Figs; 1.8and'19 of the drawi-ngs;= and the" contacts I llfi are ccrrespond-,

undesirable to -=have-- effectively variable widthcontactsw If'de'sired-thc adjustable stopsmay be;

omitted andthe insulatory portion SBa-maybe of-such-a heigh-t-"astoproperly and uniformly position -the -contacts -I 02. lfifid'engagingwith-the helical groove 12!! accurately=position the successivecams-with re-' spect to the shaft and the distribution ofthe The sameeffective action can be obtained by employing the camshaft 84 with akeyway-or groove parallel with the longitudinal axes'of-theshaft,*and-providing special contacts Izlsuch'as' .is' shown in Fig. '20of'the drawings.- These-contacts or cams I 2 I would all be spaced inthe same manner on the shaft 94 with the projections I2 Ia engageablewith a longitudinal groove or'keyway' in the shaft similar tothe helicalgroove I 25!. To' produce -the desired-coding impulses successi ecamswould have different onesof the lobes-I22 removed'so-astogive thedesired contact effect;

As illustrated'the contacts IZI are providedwith six lobes which aredesignated as 122a; I221); I220, Ii.2d5, I22e','and I227. Inthefollowing chart thecode numbersirom'l to 15 may be identified in:abinarycode by retaining the lobes-I22 asset forth inthe followingchart." Actually in this chart four--lo-bes;-i.-e., I221), I220, H2201and I221?" .are'used-ior coding-numbers frornl to-15.- Thelobes-122ccand--l22f are used to-provideother controls; ItFWilPbdunders-tood'that if-all six lobesareemployed-for coding that a muchlarger number of code numbers are available.

.1220. 122a. 1220 and 1220. 122d. 122D and 12211.

1220 and 122d. 122b, 1220 and 122d. 1222.

1221) and 122s.

1220 and 1225.

122b, 1220 and 1226;

122d and 122a.

1226', 122d and 1220. 1220, 122d and 122e,. 122b, 1226, 122d andi122e.

When the describedinFigs. 18 vto'20 is used as a cod-11.1%

circuitwhich -is periodically madeiand intere ruptedin a mannertoproduce a codewhichds a i function of theangular position of. theposition:-

The small projectionsrotary multiple contactswitch as:

11 switch shaft. The shaft of the coding switch as was mentioned abovewould be driven continuously in some fashion such as one revolution perminute or the like.

It will be understood that the coding switch may, for example, beprovided with special cams differing from the cams I to produce certainspecial functions. One such cam I30 as illustrated in Fig. 21 of thedrawings may be employed to synchronize two motor driven synchronousswitches remotely located from each other as disclosed in copendingBateman et al. application Serial No. 74,074, filed February 2, 1949,and assigned to the same assignee as the present application. The camI30 comprises an open space 130a therein which functions as asynchronizing cam in the manner fully disclosed in the above mentionedcopending Bateman application.

In Figs. 22 and 23 there is disclosed a modification of the codingswitch of Figs. 18 and 20 in which the rotatable coding cams such as IZIare dispensed with and instead a rotatable shaft I35 is provided whichhas mounted thereon a suitable conducting drum I36, The conducting drumI36 may have portions thereof insulated from each other as in the mannerof the shaft 94 described above. The drum I36 is adapted to be coveredby an insulating layer I31 having suitable openings such as I38angular-1y disposed with respect to each other as well as axiallydisplaced so as to expose predetermined portions of the conductingcylinder I36. The V-shaped portions mm of the wire-like contacts I02 areadapted to engage the conducting cylinder I36 through such openings inresponse to a predetermined angular position of the shaft I35. Thismodification of the coding switch is somewhat analagous to thearrangement disclosed in copending Black application Serial No. 45,188,filed August 19, 19i8, and assigned to the same assignee as the presentapplication. It will be understood that the insulating overlay I31 maybe constructed in various ways. For example, a suitable coating may beapplied to the cylinder I3! and appropriate portions thereof cut away.Another means of producing such an arrangement may be accomplished bydie casting a drum of conducting material from which contact segmentsprotrude at various points and using this die casting as the core orinsert in a plastic molding process so that the space between thecontact segments is filled with a plastic material. The molded cylindercan then be machined to expose the contact segments. Another means ofproducing such an arrangement might be to use an insulating drum such asI36 and apply by means of a printed circuit technique the desiredcontacts and electrical interconnections. Still another method ofaccomplishing this arrangement is to apply a mask or decalcomania to acylinder and electroplate the desired contact portions through the maskso that they protrude from the surfaces of the cylinder. The mask maythen be removed and replaced by a suitable plastic compound whichprovides a hard wearing surface so as not to be damaged by continuousengagement of the wire-like contacts I02. It has been found that formany applications the mask may be dispensed with entirely if the contactsurface portions of the conducting drum I36, such as the portionsvisible through the openings I38, are raised sufficiently above thesurrounding surface of the drum. A very satisfactory arrangement hasbeen its surface cut away by an engraving process leaving accuratelylocated raised portions which comprise the contact areas engageable atpredetermined times during a revolution of the shaft I35 by thewire-like contacts I02, the contacts I02 being prevented from touchingthe drum surface between the raised contact areas.

From the above description it will be apparent that there have beenprovided various embodiments of a position switch wherein a multiplerotary switch giving effective angular contact position and variablewidth contacts is provided. Also with very little change such a multiplecontact switch may be converted to a rotary switch which when used inconjunction with a position switch of similar construction can beemployed to convert angular shaft position to a binary code of somesort.

While there have been disclosed and described various embodiments of thepresent invention it will be obvious to those skilled in the art thatnumerous changes and modifications may be made without departing fromthe spirit and scope of the present invention in its broader aspects andit is aimed in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of the presentinvention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. In a rotary multiple contact switch, an insulating support, aplurality of relatively stationary resilient wire-like wiper contactsmounted in spaced relationship on said support, rotatable conductingmeans for selectively engaging different ones of said contacts, and aplurality of contact width adjusting means mounted on said support, onefor each of said contacts for selectively adjusting solely by limitedmovement of said contacts relative to said support the effective widthof contactive engagement of each of said contacts with said movablemeans.

2. In a rotary multiple contact switch, an insulating housing, a shaftsupported for rotation in said housing, insulating means integral withand forming a part of said housing defining a series of relatively longparallel slots in said housing, said slots defining planes perpendicularto the axis of said shaft, conducting means supported on said shaft forrotation therewith, and a plurality of resilient wiper contact armsengageable with said conducting means, each of said contact arms beingdisposed within a corresponding one of said slots, the major portion ofeach of said wiper contact arms being disposed in its corresponding slotwhereby said wiper contact arms are effectively electrically insulatedfrom each other.

3. In a multiple contact switch, a substantially rectangular insulatinghousing including means defining a chamber therein, a shaft supportedfor rotation in said chamber, insulating means integral with a part ofsaid housing defining a series of parallel slots opening into saidchamber, said slots defining planes perpendicular to the axis of saidshaft, conducting means supported on said shaft for rotation therewith,and a plurality of resilient wiper contact arms engageable with saidconducting means, each of said contact arms being supported within acorresponding one of said slots in said housing, the major portion ofeach of said wiper contact arms being disposed in its corresponding slotwhereby said wiper contact employed in which the conducting drum I36 hasarms are effectively insulated from each other.

4.-iAm-ultiplegcontact switch; comprisinssanzi-ne sulatinghousing," ashaft, jsupportedifor. rotation in said housing. meansdefining a series..ofiparal'a lel slots in said housing, said slots defining planesperpendicular to the. aXis LOf I said .shaft',=iconducting meanssupported pnisaid shaft for rotation therewith; a plurality of.resilient: .wlp'er contact arms ,engageable .-.with "said conducting:means, each of said .ioontact arms being :disposed' within one ofsaidslotsyanda plurality oi selectively ad-'. justable stop means one-foreach'otsaidcontact arms for; limiting -one i extreme. of movement ofsaid contact; arms. in said 'slot.

5." In' a rotary multiple contact 1 switch; an insulating housing, ashaft of conducting =materi-a-l supported for rotation in said housing;insulating means forming apartof said housing-and defin ing a series ofparallel slots in said housing,- said slots defining .a plurality of:planes perpendicular to the axis of said shaft, a plurality ofconducting. surfaces supported on said shaft for-rotation therewith, aplurality of resilient wiper contact arms engageable with said-conducting surf-aces, each of i said contact arms being disposedwithin:

a corresponding .one of said slotsg the major portion of eachof saidwiper contactarrns bei-ng dis posedin its correspondingslotwhereb-g-said Wiper contact arms.v are effectively insulated-from each other,and means.rfor-insulatingsome of said plurality ofconductingsurfaces-from others 4 of said conducting surfaces.-

6. In a rotary multiple contaot, multiple-phase switch, aninsulatingzhousing, a shaft ofconducting material .supportedforrotationin said-housing, insulating .meansforminga portion of said housinganddefining a series-ofparallel'slots in said housing,. a plurality ofconducting m*eans supported on said shaft for. rotation therewith, aplurality of resilient wiper contact arms engageable with saidconducting means, each-of said ing one of said sts,.the major portion ofeach of said wiper contact armsbei-n'gdisposed-in its-cor respondingslot whereby said wiper contactarms are effectively insulated fromeachother said supported for rotation in said housing, insulatingmeansiforming a part of said housing anddefining a series of, parallelslots in said housing; a ;plu= rality or" conducting means supportedyon-- said shaft for rotation therewith; -a plurality ofiresil ientwiper contactarms-engageable with said pone; ducting means,. eachofsaid-contact arms being disposed withinacorresponding one of saidslots; the major portioncf each-of said wiper contact arms beingdisposed in its corresponding; slot whereby said wiper 'contaotarms' areeffectively insulated from each other,--and -.rneans comprising aninsulating sleeve and washer for insulating some ofsaid plurality ofconducting meansfrom others of said conducting means:

8.: A rotary multiple .contactzswitch comprising a two-piece insulatinghousing including means defining a chamber therein, a shaft supportedfor rotation in said chamber, insulating means integral with one part ofsaid two-piece housing defining a series of parallel slots in saidhousing opening into said chamber, said slots being perpendicular to aplane containing the axis of said shaft, a plurality of parallel groovesdefined in 40 contact arms being disposedwithina correspondintegralwith, one part, of. said two-piece housing defining aseries?ofcparallelzslotsuin said housing. openingqinto; said: chamber, aplurality of parallel circumferentialygrooves:defined axially alongsaidsh-aft r each groove :withya corresponding -one. of:

said slots defining a, planetperpendicular .to the axis of: saidzshafti, conducting: cams supported within :said rooves :on said; shaft:for rotation: therewith,'eachcamhaving pair of .legsxextendai. ing'into, an;associatedngroove and frictionally' engaging :saidshaft-including: the walls ofgsaid associated groove, :a .:plurality of.resilient aviper contact arms ,engageable' with said cams,- each" ofsaidgzcontact arms being =..-supported within: one of said slots andhaving one, end thereofzclamped between said two partsof said housing,.the major.

part of; the unclamped.;portion, ofeach of.- said contact arms being,disposed within-. itsncorra.

spending slot, and 1 means. comprisingfiat. sides. on each of said camsto permitxapplicationxof a,

tool for positioning-z..xsai.d i; camz: relative- :.to. said Shaft:(

10: A rotary multiplecontact switch, comprisingi: -a. ;twotpiece."insulatingdhousing including means: defining a chamber therein;va shaft supe ported for rotation. in -=saidtohamber, means de fin-ing aseries .-of;-.parallels slots in said housing opening into saidcharnbenra plurality of parallel I circumferential grooves definedaxially along said shaft; each groove-with %a corresponding one ofsaidzslotst definingaplane perpendicular to the gagingsaid shaftincluding the Wallsof said associatedg-roove,:.a pluralityofresilientwipercontact arms aengageablel. with "said eams, each-=of 'said contactarms; being supported-within one ofsaid slots andclamped-betweensaid-two parts of said housing-gr the zmajo'r :part of: the uncla mpedportion Of a each 10f: said contact: arms being disposed withinsitscorrespondingoslot; means comprising fiat sidesion.eachofysaid cams topermit: appli cation of.-a tool for positioning said cam relativetosaidzshaftfito control theinstant ofcontaot of eachi camnwithiits.contact arm and means for adjustably controlling the limit of movementof each of'asaid iwip'er con-tact? arms-toward the associatedeoamsvioriselectively controlling the -effec- :tivecontactnwidth;

'11;: Arotary:multiplelcontact switch, compris lng atwoepiece'zinsulating housing; a :shaft assoarms engageable with saidcontact surfaces, the major portion of each of said contact arms beingsupported for relative movement within one of said slots and having oneend thereof clamped between the two parts of said two-piece housing.

12. The arrangement set forth in claim 2, wherein a rotatable drum ismounted on said shaft and said conducting means are contact surfaces onsaid drum disposed in predetermined positions spaced angularly andaxially on the surface of said drum.

13. The arrangement set forth in claim 2, wherein said housing is atwo-piece housing and a rotatable drum is mounted on said shaft, saidconducting means comprising contact surfaces on said drum disposed inpredetermined positions spaced angularly and axially on the surface ofsaid drum, each of said contact arms having one end thereof clampedbetween the two parts of said two-piece housing.

14. A rotary multiple contact switch comprising, a two-piece insulatinghousing including means defining a chamber therein, a shaft supportedfor rotation in said chamber, means defining a series of parallel slotsin said housing opening into said chamber, said slots beingperpendicular to the axis of said shaft, spaced contact means supportedon said shaft for rotation therewith, and a plurality of resilient wipercontact arms one engageable with each of said contact means clampedbetween the parts of said two-piece housing so as to be held ingenerally parallel relationship, one disposed for movement in each ofsaid slots.

15. A rotary multiple contact switch comprising, an insulating housingincluding means defining a chamber therein, a shaft supported forrotation in said chamber having an axially extending keyway definedtherein, means defining a series of parallel slots in said housingopening into said chamber, said slots being perpendicular to the axis ofsaid shaft, spaced contact cams supported on said shaft for rotationtherewith each comprising a pair of fingers frictionally engaging saidshaft, an extension on one of said fingers engageable with said keywayand a plurality of resilient wiper contact arms one engageable with eachof said contact cams supported by said housing so as to be held ingenerally parallel relationship, one disposed in each of said slots.

16. A rotary multiple contact switch comprising, an insulating housingincluding means defining a chamber therein, a shaft supported forrotation in said chamber having an axially extending keyway definedtherein, means defining a series of parallel slots in said housingopening into said chamber, said slots being perpendicular to the axis ofsaid shaft, spaced contact cams supported on said shaft for rotationtherewith each comprising a pair of fingers frictionally engaging saidshaft, an extension on one of said fingers engageable with said keyway,each of said contact cams comprising a plurality of lobes, and aplurality of resilient wiper contact arms one engageable with the lobesof each of said contact cams supported by said housing so as to be heldin generally parallel relationship, one

16 disposed in each of said slots, said lobes being selectivelyremovable to give predetermined desired contacting in response torotation of said shaft.

17. A rotary multiple contact switch comprising, an insulating housingincluding means defining a chamber therein, a shaft supported forrotation in said chamber having a helical keyway defined therein, meansdefiining a series of parallel slots in said housing opening into saidchamber, said slots being perpendicular to the axis of said shaft,spaced contact cams supported on said shaft for rotation therewithcomprising a pair of fingers frictionally engaging said shaft, anextension on one of said fingers of each of said cams engageable withsaid helical keyway, and a plurality of resilient wiper contact arms oneengageable with each of said contact cams supported by said housing soas to be held in generally parallel relationship, one disposed in eachof said slots.

18. The rotary multiple contact switch of claim 1 in which saidrotatable conducting means comprises a rotatable disk having a somewhatradially disposed conducting member associated therewith whichconducting member has a variable width in a direction along the radiusof said disk, and wherein said wire-like contacts selectively engagesaid conducting member in response to rotation of said disk, theselective adjustment of said contacts controlling the effective width ofcontacting engagement of said conducting member with each of saidcontacts.

19. The rotary multiple contact switch of claim 1 in which saidrotatable conducting means comprises a rotatable disk having a somewhatradially disposed conducting member associated therewith whichconducting member has a variable width in a direction along the radiusof said disk, and wherein said wire-like contacts selectively engagesaid conducting member in response to rotation of said disk, theselective adjustment of said contacts controlling the effective width ofcontacting engagement of said conducting member with each of saidcontacts and also the position of the disk when contact is made.

FRED KRAHULEC.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,579,304 Goddard Apr. 6, 1926 1,822,700 Hunter Sept. 8, 19311,869,648 Ashworth Aug. 2, 1932 1,982,982 Crozier Dec. 4, 1934 2,055,031Hutchings Sept. 22, 1936 2,135,832 Obergfell Nov. 8, 1938 2,196,409 BelzApr. 9, 1940 2,277,899 Aufiero Mar. 31, 1942 2,520,258 Pittman et a1Aug. 29, 1950 FOREIGN PATENTS Number Country Date 49,090 Australia Feb.1, 1911 143,497 Switzerland M Jan. 16, 1931

